Finding Common Errors

I've recently started using the 'computer analysis' feature on chess.com to review my games. While I've found it useful, I am looking for a couple features that it doesn't have. I was wondering if anyone knew if there was a program that could do the following:

1. Explain why a move was a mistake/inaccuracy/blunder - The blunders are often fairly clear, but sometimes the computer analysis indicates that I've made a mistake and while it says which move is the 'better' one, I don't understand why.

2. Analyze multiple games and tell me what a common trend is in my errors. Say I have it look at 100 completed games and it tells me that I often overlook a particular thing, or regularly miss certain patterns, etc.

I've started to study chess seriously and while I've played a reasonable number of games, and have started to learn new things via the videos/articles/chess mentor, it would be great to have a program be able to point out the areas that I'm weak so that I can focus on those.